Dredging devices may be used to relocate particulate matter, such as rocks, sand, mud and the like, that is submerged in water. One known dredging device comprises a suction head through which a pressurised fluid is pumped. The fluid is channelled through a venturi to create a pressure differential that causes particulate matter to be sucked into the suction head and entrained with the pressurised fluid. The stream of fluid acts as a transport medium to convey the particulate matter to a different location underwater or a collector above the surface.
This form of dredging device is commonly used in the offshore and onshore oil and mining industries, such as for construction, repair and mining applications, for example. In use, the suction head may be secured to a remotely operated under water vehicle (or “ROV”) that may be able to operate in seawater at depths of up to 30,000 feet (around 9,000 meters) or more. The ROV can be controlled remotely from the surface. A surface mounted pump can be used to pump the pressurised fluid to the submerged suction head. Alternatively, the water pump can be mounted directly to the ROV and powered by the ROV or remotely using a surface mounted power source. Alternately, the suction head can be mounted to a frame that can be guided by a diver.
An embodiment of the present invention seeks to provide an improved suction head for a dredging device, or at least to provide the public with a useful choice.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.
It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.